Leicester City won 2-1 on Friday night and results on Saturday sealed their top-flight return. Photograph: Carl Recine/Action Images

Leicester City are back in the Premier League for the first time in a decade after third-placed QPR's failure to find a late equalising goal at Bournemouth guaranteed Nigel Pearson's side promotion.

Leicester, who beat Sheffield Wednesday 2-1 on Friday night to put themselves on 89 points for the season, extending their unbeaten league run to 21 games, needed Harry Redknapp's Rangers to lose on his return to the south coast club, and Derby to fail to beat Middlesbrough, to be sure of promotion.

And, as Steve McClaren's Derby lost 1-0 on his return to the Riverside, QPR also ended up pointless despite nearly coming from behind right at the end at the Goldsands Stadium.

Leicester's last game in the Premier League was a 2-1 defeat at Arsenal in 2004 as Micky Adams' side were relegated. Since then City have been through 17 managers or caretaker managers, two changes of ownership and a season in League One.

Leicester's goalkeeper, Kasper Schmeichel, said the squad would now refocus their efforts on securing the Championship title before they look ahead to next season. "Achieving promotion was our aim this season but we want to win the league now, no question of that. We've got six games left and we want to win the Championship.

"Tonight we celebrate but everyone who knows the mentality of the team or the staff knows as soon as tonight's over we get back to work. We want to keep pushing on and we'll be back working hard ahead of Tuesday's game [at home to Brighton]. Then the real hard work starts to stay in the Premier League."

Schmeichel told Sky the City players had never doubted they would succeed despite the unpredictability of life in the Championship.

"We've had belief all the way through the season. I think we can look back and see when we scored late goals and had that never-say-die attitude. That helped us immensely and it's testimony to the players and staff that everyone's worked really well together.

"We never panicked. We stuck at our game and knew we were playing good football. Every team has results which aren't going to go their way but we won nine games in a row and that really propelled us to the top of the league.

"It's a great day and I'm really really delighted – but it's by no means over."

Schmeichel – son of the former Manchester United goalkeeper Peter – said he was particularly looking forward to next season's visit to Old Trafford, and to discussing it with his father.

He said: "My phone's been jammed ever since but no doubt I'll be speaking to him. To go to Old Trafford is the ultimate one, having grown up watching lot of games there. It's been my dream for as long as I can remember. That's a great one but in the Premier League every game is great to be involved in, so I'm just looking forward to it."

Schmeichel added: "It's going to be a lot more enjoyable summer than the last one. Everyone behind the scenes deserves massive credit for working hard towards the same goal."

The club's captain, Wes Morgan, gave his reaction to the Leicester Mercury, saying: "It feels fantastic. We did our job on Friday night and we still have six games to go so we just want to concentrate on becoming champions now.

"It is definitely the greatest achievement of my career so far to achieve promotion. It is amazing and something I haven't done before. To captain Leicester and do it is even more special."

The former Leicester striker Gary Lineker was also quick to acknowledge the club's achievement, tweeting: "Leicester City are promoted to the Premier League. A sentence I've been waiting to say for 10 years."